The AR-15 is America’s most popular rifle. It’s no surprise why:

It’s versatile, lightweight, and accurate — especially if you use the best scope for AR-15. And that’s why the original Armalite AR-15 (later adopted as the M16) became the United States rifle of choice. But we didn’t discover the AR-15 on accident, it took the Vietnam War to discover it. In the dense jungles of Vietnam, the first U.S. troops were deployed. Their weapon? The M14.

They thought they were well-equipped. They were wrong. As it turns out, the bushwackin’ guerilla armies of Vietnam had an even better rifle: the AK-47. In comparison to the M14, the AK had a larger magazine (30 rounds), less recoil, and was more controllable in full auto. The result? U.S. troops were at a distinct disadvantage. They needed a better assault rifle FAST. So…

The U.S. Army Searched For A New Assault Rifle

More specifically, one that was capable of high-velocity, full- and semi- auto fire, possessed a twenty-shot magazine, weighed 6 pounds loaded, and was still able to penetrate a standard U.S. M1 helmet at 500 yards. So they asked gun manufacturers to submit their designs. Out of the few designs submitted, the select-fire AR-15 blew the Army away.

Essentially a scaled down AR-10, the AR-15 was lightweight, accurate, and had something no other gun before it had: a .223 caliber bullet. This caliber made the AR-15 lighter and allowed soldiers to carry more ammo. As a result, soldiers could sustain fire power longer during firefights, and when compared against the M14, the AR-15 outperformed it in nearly every department — reliability, recoil, accuracy, cost and ease of production, and weight. However, the Army was still reluctant to adopt the rifle. That was until the...

Air Force Ordered A Big AR-15 Shipment

The Air Force didn’t care what the U.S. Army thought about the AR-15. They knew the gun was good, and in May of 1962 they were finally approved to buy a whopping 8,500 AR-15 rifles along with 8,500,000 rounds of ammunition to give to Air Force men.

However, not all the early guns went to Air Force men. An additional 1,000 AR-15s went to the Pentagon’s Advanced Research Projects Agency, who then shipped them to the allied South Vietnamese Army for testing. The result?

The South Vietnamese fell in LOVE with the AR-15. So much so that the South Vietnamese government asked the U.S. to make the AR-15 the standard rifle for its forces. Although it would take a bit of time (and politics) for the request to be accepted, when the AR-15 finally arrived in 1964 as the officially adopted M16…

The North Vietnamese Trembled

In fact, the M16 earned the name “black rifle” by the enemy. Why is that?

When compared to the Vietnam’s weapon of choice (AK47), the M16 won. It was more accurate, lighter, and had very low recoil. These benefits offered an unparalleled advantage in the dense jungles of Vietnam, where the average firefight range was between 30-50 yards.

Highly Desirable Documented Rare Original Vietnam Era Fully Automatic Class III/NFA Chinese AK47. Sold for $48,875 in May 2016

Before the M16, U.S. soldiers were sitting ducks, absorbing a barrage of bullets from the enemy’s AK-47. The Army couldn’t keep up until the M16 arrived. When it did, it effectively outgunned the North Vietnamese, saving countless lives. As a matter of fact, the Blue Ribbon Defense Panel concluded that the M16 saved over 20,000 US soldiers lives during the war. In comparison, if the M14 stayed, those 20,000 servicemen would’ve likely died thanks to the combat advantage the AK-47 gave to the North Vietnamese. And due to the military’s adoption of the M16...

Colt Sold A Semi-Automatic AR-15 To Everyone

Colt marketed the semi-automatic only version of the M16 to everyone, and called it the SP1 Model AR-15 Sporter.

Excellent Very Early Production Colt AR-15 Model SP-1 Semi-Automatic Rifle, Serial Number "SP00156" with Extra Magazine. Sold for $10,350 in May 2016

It didn’t matter whether you were a civilian or law enforcement, anyone could enjoy the benefits of the rifle once the select-fire function had been removed. When Colt’s patent expired in the 1970s, other gun manufacturers began to copy the design, setting the stage for the endless number of AR manufacturers we have today.

And it wasn’t long until the AR-15 became “America’s Rifle,” with over an estimated 11 million of them in the circulation. That’s why the AR-15 is used by home defenders, hunters, target shooters, competition shooters, SWAT, and law enforcement agencies worldwide.